Finding the Fourth Proportional to 21,013.16, 31,518.66 and 5,430.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,013.16 : 31,518.66 = 5,430.38 : x
2. Step 2: Convert to fraction form
   21,013.16/31,518.66 = 5,430.38/x
3. Step 3: Cross multiply
   21,013.16x = 31,518.66 × 5,430.38
4. Step 4: Simplify right side
   21,013.16x = 171,158,300.89
5. Step 5: Solve for x
   x = 171,158,300.89/21,013.16
6. Step 6: Final answer
   x = 8,145.29